Enabling Java Debugging for Your Server

The JVM can be started in debug mode and can be attached to a
JPDA (Java Platform Debugger Architecture) debugger. When you enable
debugging, you enable both local and remote debugging.

Sun Java System Web Server's debugging is based on JPDA software.
To enable debugging, perform the following tasks.

Enable JVM Debugging

Click the Configurations
tab to see the list of available configurations and select the configuration you
need.

Click Java > JVM Settings tab.

Under Debug Java
Settings, select
the Enable Debug checkbox.

Provide JVM options as necessary by clicking the New button.

The default JPDA options are as follows:

-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=7896

If you substitute suspend=y, the JVM starts
in suspended mode and stays suspended until a debugger attaches to
it. This is helpful if you want to start debugging as soon as the
JVM starts. To specify the port to use when attaching the JVM to a
debugger, specify address=port_number. Check out
the JPDA documentation for a list of debugging options.